Pencil



0. HUBER April 14, 1931.

PENCTL Filed June 6, 1929 m 5 MM mm 9. W 1 a Patented Apr. 14, 1931 UNITED STATES PATENT OFFICE OTTO HUBER, OF ASTORIA, NEW YORK, ASSIGNOR TO EAGLE PENCIL COMPANY, OI

NEW YORK, N. Y., A CORPORATION OF DELAWARE PENCIL Application filed June 6, 1929. Serial No. 368,862.

This invention relates generally to what are known in the art as mechanical pencils, and has particular reference to mechanical pencils of the kind in which a feeding and retra cting movement of the lead or other marking material is effected by a relative rotation of two of the exterior parts of the pencil.

An object of the invention is to provide a construction of the kind mentioned which is simple in construction and which cannot be damaged by continuing to rotate the parts for effecting movements of the lead after the limits of such movements have been reached. This object is attained in such a way that the parts are few in number and of a relatively inexpensive nature, while, at the same time affording maximum protection without interfering with the efliciency of the feeding devices.

This result is obtained by introducing into the feeding mechanism a clutch which will yield or slip when the relative manual movement of the two main parts of the pencil is continued beyond the point necessary to move the lead the full distance in or out. This prevents the more delicate parts of the feeding mechanism from being strained or damaged and results in long life even though the parts are not heavily constructed.

With the above and other objects in view the invention consists in a novel construction and combination of parts, the novel features of which are pointed out in claims appended hereto and an illustrative embodiment of which is hereinafter described with reference to the drawing accompanying and forming a part of this specification.

In said drawings:

Fig. 1 is an elevation of a pencil with part of the casing cut away to show details of the improvement.

Fig. 2 is an elevation of the same pencil with all of the parts of the casing omitted and one of the remaining parts broken away to show other parts of the invention.

Fig. 3 is an enlarged detail of some of the parts in Fig. 2, the parts in the figure also being shown in disconnected relation.

Fig. 4: is a section on the line 44 of Fig. 2.

The construction of the pencil shown in the drawing comprises a casing made up of the portions 10, 11 and 12, the portion 11 being the usual tapered finishing shell and the portion 12 a collar or band secured on the casing. The upper portion 13 of the band 12 is formed to provide a bead and extends up far enough to afford a support for a cylindrical receptacle 1 1 for an eraser 15. Frictionally engaging the portion 15 is an outer cap 16 which is removable to ex ose the eraser. The eraser 15 is also remova 1e to give access to a barrel for leads within the member 17, which member is integral with the portion 1 1 above referred to. The member 17 is rotatably supported within the interior of the portion 10 of the casing. It is apparent that by turning the portion 14 or the cap 16 relative to the portion 10 of the casing the member 17 will also be turned. The member 1? acts through mechanism to be described, to feed or retract a lead.

The lead feeding and retracting mechanism comprises the usual split tube 21 which is threaded into a collar 22 tapered as at 23 to engage within the tapered portion 11 of the casing. These parts may be driven in to the casing or otherwise secured so that the member 22 and the split tube 21 rigid therewith are immovable relative to the casing members 10 and 11.

Mounted within the split tube 21 is a carrier tube 25 which may be split to form a clutch at the portion engaging the lead and within the carrier tube is a feed bar of the usual type, which is permitted to have a limited movement relative to the carrier tube so as to eject the remainder of a lead or to free the end of the carrier tube to receive a new lead. The carrier tube and feed bar are not shown in detail because any suitable construction may be employed; in fact the carrier tube may be omitted and the feed bar only employed in case the lead retracting feature is not used. The feed bar has, however, one or more projections 27 which project through the split tube into a spiral slot 28 in a helix 29.

lVhen the parts are in assembled position the helix 29 is limited to a rotary movement and its slot 28 will act upon the portions 27 of the feed bar to move the bar inone direction or the other as desired.

The upper end of the helix has secured to it a member 31 which forms a part of the clutch above referred to in a general Way. The member 31 has a cylindrical portion of greater diameter than the rest of the member and in addition to being tightly fitted on the helix is secured thereto by forming the material of the member as at 32 to tightly engage the edges of a continuation of the helical slot 28. This is a convenient way of securing the two parts together,-but it is ob vious that the same result can be accomplished in other ways.

The split tube is formed at one end as shown at 33 to provide angularly disposed wings which have slots engaging a portion 34 integral with either the clutch member 31 or the helix 29. In the preferred construction the portion 34 is produced by turning the end of the helix 29 inward to provide a flange engaging the slots in the wings 33, thereby preventing an endwise relative movement of the helix and split tube.

The lower portion 35 of the rotary member 17 is constructed to yieldingly grip the clutch member 31 referred to above. For this purpose the member 17 is constructed of material which has a certain amount of resiliency or the member 17 may be provided with a separate portion 35 of spring steel or other material having the same quality. In either event the portion 35 will be provided with one or more slots 36 so as to provide in efiect a spring clutch member to grip the other member 31 of the clutch. The portions 35 and 31 cooperate in such a way as to drive the feed bar and associated carrier tube, if a tube is used, back and forth to feed the lead in or out. When the limit of the feeding movement in either direction has been reached, however, the portion 35 will slip on the portion 31 thereby preventing the force applied through the member 17 from twisting the helix 29 out of shape or damaging the parts contained within the helix because of the force applied through the projections 27 on the feed bar.

From the foregoing it is apparent that while the pencil is quite simple in construction it is not subject to damage from forcing the feeding mechanism in either direction. The construction is also of such a nature that the friction clutch will not wear rapidly in use so that the protection feature will remain in efficient condition for an indefinite length of time.

In explaining the invention it has been necessary incidentally to describe the construction in considerable detail. This construction, however, is only a preferred one and it is not the desire to be limited by details except as they appear in the claims which follow.

What is claimed is:

1. A pencil comprising a-casing, a member manually rotatable in the'casing and having a tubular inner end, said tubular inner end being slotted to give resilient expansion, a split tube rigid with the casing, a lead feeding element slidably supported in the split tube, a helix having its thread engaging projections on the lead feeding element, and a cylindrical head onthe helix having a sliding, frictional engagement with the interior of the slotted end of the aforesaid manually rotatable member.

2. A pencil comprising a casing, a member manually rotatable in the casing and having a tubular inner end, said tubular inner end bein slotted to give resilient expansion, a split tu e rigid with the casing, a lead feeding element slidably supported in the split tube, a helix having its thread engaging projections on the lead feeding element, a cylin-, drical head on the helix having a sliding frictional engagement with the interior of the slotted end of the aforesaid manually rotatable member, and means on the manually rotatable member cooperating with the interior of the casing for holding the manually rotatable member in correct longitudinal relation with the helix.

In testimony whereof I hereto affix my signature.

OTTO HUBER. 

